Currently we are involved in three studies: (1) The effect of carben- oxolone of gastric mucus and DNA. Carbenoxolone is one of the few drugs which was shown to be of value in the medical treatment of duodenal ulceration. Our results suggest that it has no effect on gastric acid and pepsin secretion, but it rather enchances the gastric protective mechanisms by altering gastric mucus secretion (and possibly making it more resistant to acid-pepsin di- gestion) and by decreasing cellular exfoliation. (2) We have established normal transit times. flow rates and volume (indirectly surface area) values in the proximal jejunum of normal subjects, using the method of triple luman perfusion and the instantaneous injection of a dye. Work is presently in progress to study the effect of surgery, and in particular, vagotomy on these parameters. (3) Finally we are continuing our study on the relationship of the relationship of the physico-chemical status of plasma steroids to stress ulceration. Preliminary results suggest that most cases are associated with a long-term increase in free plasma cortisol, increase of total plasma cortisol and in many cases a fall in CBG. This latter factor may play an important role in the stress ulcerogenesis of patients with relatvely long-term sepsis.